This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry.

The bug that never crashed

The scariest bug I caught this month never threw a stack trace. It never paged anyone. It just quietly made an AI agent dumber, on repeat, and handed the blame to the model.

Here is the whole story, because the way I found it turned out to matter more than any single fix.

Where it started